IIS 7.5 error: Handler “PageHandlerFactory-Integrated” has a bad module “ManagedPipelineHandler” in its module list

Today I installed Clean Windows Web Server 2008 R2 64-bit with IIS 7.5. To my surprise opening .NET 4.0 application I received the following error: IIS 7.5 Detailed Error – 500.21 – Internal Server Error Server Error in Application “DEFAULT WEB SITE” Internet Information Services 7.5 [Error Summary] HTTP Error 500.21 – Internal Server Error […]